Improvement in revolving-hook sewing-machines



A.'C. VAN SANT.

REVOLVING-HOOK SEWING-MACHINE, No.17Z,676'." Patented Jan.25,1876..

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N. PETERS, PHOTO-LITNOGRAPNER, WASmNGYON. D O.

UNITED STATES PATENT OFFICE.

ADAM o. VAN SANT, or" PEORIA, ILLINQIS, ASSIGNOR To WHEELER AND \VILSON MANUFAOTURING COMPANY, OF BRIDGEPORT, CONNECTICUT.

IMPROVEMENT IN REVOLVING-HOOK SEWING-MACHINES.

Specification forming part of Letters Patent No. 172.676, dated J annary 25, 1876 application filed August 13,1875. I I

To all whom it may concern:

Be it known that I, ADAM G. VAN SAN'I, of the city and county of Peoria, in'the State of Illinois, have invented certain Improvements in Sewing-Machines, which improvements are fully set forth in the following specification,

pliedto the machine as when in operation, the

parts of eachbeing lettered as follows:

1}, arm of machine; B, frame of machine; 0, rotating hook; D, ring-slide; E, stop; F, metal spoolgor bobbin; G, bobbin-case; H, leader; I, loop-controller; J, loop of upper thread K, tension-regulating notch, while L and M show different positions of the under thread.

The construction and operation of my invention are as follows:

g The metal spool or bobbin for containing the under thread (shown at F, Fig. 2)'is constructed essentially as heretofore, except that it is much thicker. The bobbin-case Gris constructed in the shape plainly shown in the drawings, and is of sufficient depth that when placed over the bobbin, as -in operation, its edges may" completely cover the opening in the circumference of the bobbin. From the top of the bobbin-case extends a short projection, as shown at H, which I term aleader, and from the bottom of the sameextends a longer projection, which is shaped as shown at I, which I term a loop-controller, and in the edge of its rim, near the leader H, is formed a passage for the thread, which I term a tension-regulating notch. (Shown at K.) The center of the recess in the bobbin-case is raised slightly above the general surface, as represented more particularly by the sectional view in Fig. 2. The ring-slide I) I construct the same as heretofore used, except that upon the top of the same I place a projection or spur, as shown at E, which I term a stop.

As'the parts of my invention are plainly shown in the drawings, the foregoing brief description, together with the further reference to them in explaining their operation,

will be sufficient to render their construction clearly understood. r V 7 To prepare the machine for work, the bob bin F, after being filled with thread, is placed within the bobbin-case-G, the thread passing vents the casefrom turning with the hook, and holds the loopcontroller I always in one position, as seen in Fig. 1.

When in operation, the rotating hook revolvesin the direction indicated by the arrow, (the thread in thebobbin being wound in an opposite direction,) while the fabric being sewed, if passing through a machine standing as shown in the drawings, would-be fed toward the observer.

While the interlocking mechanism used in the Wheeler and Wilsonmachine is now well understood, yet it will be necessary to refer to its operation, both with and without my improvement, in order that the application of my improvement thereto may be clearly comprehended. Its operation is as follows As the needle is forced through the fabric, it passes in close proximity lo the rotating hook, which is shown at U, and as it starts to rise, thus forming a loop of the upper thread, the loop is caught upon the point of the rotating hook and there held until the hook has performed a part of a revolution, when that portion of the loop which was back of the point of the hook enters a diagonal groove, which conducts it toward the face of thehook, where it is chamfered off in such form as to cast the loop off the face of the hook and over the metal spool or bobbin (which has formerly been used without a case) which contains the under thread,th us interlocking the two threads.

It will be seen that even after the loop has been thus passed around the bobbin, the stitch is still incomplete, the hook being incapable of completely disengaging itself from thenlfoop; preparatory to making. the next stitcl1.-. Th isiaccomplished in my invention by means of the loop-controller I, the operation of which is as follows:

As the loop ofthe thread is being carried W'the hook-v aronnd'l the Botbnrcase which incloses the: bobbin containing the under thread, before the Operation is entirely com plete, the'loopcomesin contact with the loopcontroller, which gradually arrests its passage, and, as the loop must pass over the loop-controller also to complete its passage around the under thread, it is -evident-that in doing so the loop will be elongated, and the controller is constructed of such width and shape that the strain upon the thread causedrby its-passage over the controller'jwill be'just sufficient todraw theloop from behind the poi'ntot' the hook. After-performing this office,- the loopis retained upon the-loop-com" tfro'ller," shown'b'y the li'ne' J in-thexlrawingsy until the hook enters the succeedin'gloop, when,

ast'he -hook' draws thread for tliene'xt stitch, it" s-lides'ofl" the end' of the controllerand is drawn up into the fabric, thus'c'omp'leting the stitch;-

It will b'e' seen that" part'ofthe'slack thread whichforlnsthis" loopisdrawn upby the needle as it penetratesthefabricfor the next stitch,and itiis evident that more-Of 'the-lbop will betbnstaken'up in sewing upon thick than upon thin fabrics. To permit'this, the

loop-controller is so shaped that a'sthe' loop" approaches its upper end the loop will be" sliic'kened snffi'cient-ly to givethe necessary amount ot'threa'd. In sewing'thick fabrics, therefore,-the 1oopmcre1yslidesenoughnieairer' the upper endfof"the'contro'ller' to givethis necessary amonnt'of' thread, and ist-here ret'ained; preparatory to being dr'awn: up" durin g theformation of the next stitch;

I do not, however, confinemys'elf'to the: use of w the loop-controller I, as the leader'H and the tLensioxr-regulating notch K perform inriortan'tfunctions in'and of themselves, whether used" in connection with the loop-controllerl or'any other device which willla'ccomplish the same purpose. As, for instance, the end of the under thread being passed through the leader H, a e-described; even if extending only far eno'u toreach the fabric] bein g. sewed; will be. always held by thelea'der H in exactly'the proper position tob'e caught by the: E I

to secu're'byLetters Patent, is v loopwof the upper thread; and requires no furtherattention fromtheoperator whatever,

tension-regulating notch K, in combination while, as now in use, av sufficient length of thread must be" leftextendin gffro'm the-bobbinto be: either: m'a'de fast orheld by'the' opera-tor,

there'by incurring a waste of thread, and" re- 1 jthe bobbin-case G, constructed to operate'as quiring the careful attention of the" operator atthe beginningfof every seam,

Again, with" the bobbin as heretofore em: ployed, it" the machine is turned back-ward; which frequently occurs with beginners, on reversing the motion the under thread will usually be caught behind the rotating hook,

andthesewing. can only be continued-by ref moving the worka'nd rearran gi'ngthe threads, while with myi-mprovement, the under thread being held by the leader H entirely away from thepoint of therotating hook, it can,

- under no' cirou'mstances, be caught by it, and? sew with as much certainty as turned only account of the constantly-increasing tension of the underthread as'it'becom es-exha'usted from the bobbin, owing to the fact that the thread is more easily drawn from the circumference 0f the bobbin, as when full, than from nearer its center, as when nearly'empty, and'conse' '1 iquent-ly requiring a frequentchange of the tension of "the upper thread to insure a uni- .fform" interlocking; of the" two threads in the I itabrie-T y This tendency ofthe tension oft-he under thread to increase as the thread becomes ex @hausted is counteracted in my improvement !in the following manner: When the bobbin is jfull, thethre'ad, in drawing from the bobbin,

;is drawn in the course indicated by the line lLshown in the case (dc-Fig, 2, and in its pas-- sage through-thetension-regulatingnotch it is drawn with sufficient force against the rim of g'thebobbin-case toimaterially increase its tenjsion, while, as the thread becomes exhausted it" drawsmore and-morein the-direction of the line-Min the same figure, which diminishes' Ithe friction caused by its- -passage'through'the: fnot'ch, Also, as the threa'dd'rawsmore in the lla'tt'er direct-ion it' has a tendency to lift the bobbin, and' thereby diminishesthe friction, betweenthe lower edge of the bobbin and the,

case, which tendency increases as the thread approaches the center, and though the dc siredle'ft'eet is duemore to theformer than the I latter, the result of these twoinfluences is a uniformity of tension: upon the under thread unattainable with the open bobbin.

I' do; not confine myself tothe exact loca--' ;-tion ot'the tension-regulating notch in rela- =ti'on to the leader H, shown inthe-drawing,'- but it may'be'moved farther'to the right or.

left, to'exert moreor less of this controlling,

, influence upon theiunderthread, as extended experience may prove necessary.

What I claim as my invention, and desire 1. The bobbi'mcase G, provided with the iwith the leader H, andstop E, all constructed;

;to1op'erate as shown and described;

2; The"loop controller'I,in combination with v shown and described. 

